icnd02_internetwork concepts overview

8/10/2019 ICND02_Internetwork Concepts Overview

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2000, Cisco Systems, Inc. 2-1

Chapter 2

Internetworking

Concepts Overview


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2000, Cisco Systems, Inc. www.cisco.com ICND v1.0a2-2

Objectives

On completion of this chapter, you will beable to perform the following tasks:

Describe how data traffic is exchangedbetween source and destination devices

Identify the roles and functions of a hub,switch, and router, and where they best fit in

the network Select the appropriate Cisco equipment for a

given set of network requirements


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Defining Componentsof the Network

Main OfficeBranch Office

HomeOffice

MobileUsers

Internet


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Floor 2

Floor 1

Server Farm

Defining the Componentsof a Network (cont.)

BranchOffice

Telecommuter

ISDN

Remote Campus


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OSI Model Overview

Application(Upper)Layers

Session

Presentation

Application


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OSI Model Overview

Data FlowLayers

Transport Layer

Data Link

Network Layer

Physical

Application(Upper)Layers

Session

Presentation

Application


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Role of Application Layers

TelnetFTP

User Interface

EXAMPLES

Application



TelnetFTP

ASCIIEBCDICJPEG

User Interface

How data is presented

Special processingsuch as encryption

EXAMPLES

Presentation

Application




TelnetFTP

ASCIIEBCDICJPEG

Keeping differentapplications

data separate

User Interface



Operating System/Application Access

Scheduling

EXAMPLES

Session

Presentation

Application




Keeping differentapplications

data separate

User Interface



TelnetFTP

ASCIIEBCDICJPEG

Operating System/Application Access

SchedulingTransport Layer

Data Link

Network Layer

Physical

EXAMPLES

Session

Presentation

Application




Role of Data Flow Layers

EIA/TIA-232

V.35

EXAMPLES

Physical

Move bits between devices

Specifies voltage, wire speed and

pin-out cables



802.3 / 802.2HDLC

EIA/TIA-232

V.35

EXAMPLES


Data Link

Physical

Combines bits into bytes and

bytes into frames Access to media using MAC address

Error detection not correction



pin-out cables



802.3 / 802.2HDLC

EIA/TIA-232

V.35

IPIPX

EXAMPLES


Network

Data Link

Physical






pin-out cables

Provide logical addressing whichrouters use for path determination



TCPUDPSPX

802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

EXAMPLES


Transport

Data Link

Physical

Reliable or unreliable delivery

Error correction before retransmit






pin-out cables

NetworkProvide logical addressing whichrouters use for path determination



TCPUDPSPX

802.3 / 802.2HDLC

EIA/TIA-232V.35

IPIPX

Presentation

Application

SessionEXAMPLES


Reliable or unreliable delivery

Error correction before retransmit






pin-out cables

Transport

Data Link

Physical

NetworkProvide logical addressing whichrouters use for path determination



Encapsulating Data

Transport

Data Link

Physical

Network

Upper Layer Data

Upper Layer DataTCP Header

DataIP Header

DataLLC Header

0101110101001000010

DataMAC Header

Presentation

Application

Session

Segment

Packet

Bits

Frame

PDU

FCS

FCS



Upper Layer Data

De-encapsulating Data

LLC Hdr + IP + TCP + Upper Layer Data

IP + TCP + Upper Layer Data

TCP+ Upper Layer Data

Upper Layer Data

0101110101001000010

Transport

Data Link

Physical

Network

Presentation

Application

Session



Application

Presentation

Session

Transport

Network

Data Link

Physical

OSI Model PDU Functional Responsibilities Examples

Written Exercise: OSI Model



Physical Layer Functions

Defines

Media type

Connector type

Signaling type

802.3

Physical



Physical Layer: Ethernet/802.3

Hub

Hosts

Host

10Base2Thin Ethernet

10Base5Thick Ethernet

10BaseTTwisted Pair



Hubs Operate at Physical layer

A B C D

Physical

All devices in the same collision domain

All devices in the same broadcast domain

Devices share the same bandwidth


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Hubs: One Collision Domain

More end stations means

more collisions CSMA/CD is used


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Data Link layer Functions

Defines

Physical source anddestination addresses

Higher layer protocol(Service Access Point)associated with frame

Network topology

Frame sequencing Flow control

Connection-orientedor connectionless

DataL

ink

Physical

EIA/TIA-232

v.35

802.2

802.3


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DataSource add FCSLengthDest add

Variable266 4

0000.0C xx.xxxx

Vendorassigned

IEEE assigned

MAC Layer - 802.3

Data Link Layer Functions (cont.)

Preamble

Ethernet IIuses Type

here and

does not use802.2.

MAC Address

8# Bytes


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DataDest

SAP

Source

SAP

DataSource add FCSLengthDest add

Variable11

802.2 (SAP)

MAC Layer - 802.3

Data Link Layer Functions (cont.)

Ctrl

1 or 2

3 2

Preamble

DataDest SAP

AASource SAP

AA

Variable11

802.2 (SNAP)

Ctrl

03

1 or 2

OR

OUIID

Type

# Bytes

# Bytes

S i h d B id O


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Each segment has its own collision domain

All segments are in the same broadcast domain

Data Link

Switches and Bridges Operateat Data Link Layer

OR1 2 3 1 24


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Switches

Each segment has itsown collision domain

Broadcasts areforwarded to allsegments

Memory

Switch


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Network Layer Functions

Defines logicalsource anddestination

addressesassociated with aspecific protocol

Defines pathsthrough network

Interconnectsmultiple data links

Network

IP, IPX

DataLink

Physical

EIA/TIA-232

v.35

802.2

802.3


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DataSource

address

Destination

address

IP

Network Layer Functions (cont.)

Header

172.15.1.1

NodeNetwork

LogicalAddress

Network Layer End Station Packet


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11111111 11111111 00000000 00000000

10101100 00010000 01111010 11001100

BinaryMask

BinaryAddress

172.16.122.204 255.255.0.0

172 16 122 204

255

Address Mask

255 0 0

Network Host


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Routing Table

NET INT Metric

124

S0S0E0

100

1.0 4.0

1.3

E0

4.3

S0

2.2

E0

2.1

S0

4.1

4.2

1.1

1.2

Routing Table

NET INT Metric

124

E0S0S0

001

Logical addressing allows for hierarchical network Configuration required

Uses configured information to identify paths to networks



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Routers: Operate at theNetwork Layer

Broadcast control

Multicast control

Optimal pathdetermination

Traffic management

Logical addressing

Connects to WANservices


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Using Routers to ProvideRemote Access

Internet

Telecommuter

Branch Office

Modem or ISDN TA

Mobile User

Main Office


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Transport Layer Functions

Distinguishes betweenupper layer applications

Establishes end-to-end

connectivity betweenapplications

Defines flow control

Provides reliable orunreliable services fordata transfer

Net

work

IPXIP

Trans

port

SPXTCP UDP

R li bl T L


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Reliable Transport LayerFunctions

Synchronize

Acknowledge, Synchronize

Acknowledge

Data Transfer

(Send Segments)

Sender Receiver

Connection Established


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Network Device Domains

Hub Bridge Switch Router

Collision Domains:

1 4 4 4

Broadcast Domains:

1 1 1 4


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Product SelectionConsiderations

Provides functionality and features you needtoday

Capacity and performance

Easy installation and centralized management

Provides network resiliency

Investment protection in existing infrastructure

Migration path for change and growth

Seamless access for mobile users andbranch offices

P d S l i


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First select WANtechnology solutionsbased on the following:

Availability of service

Bandwidth requirement

Cost

Second, choose productsthat support selected WANsolutions

Product SelectionConsiderations (cont.)

Costper

Month

Usage

Leased Line, T1

Modem/ISDN

Frame Relay

0


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Selection Issues:

Need for 10 Mbps, 100 Mbps, or 1000 Mbps onmedia

Need for trunking and inter-switch links

Workgroup segmentation (VLANs)

Port density needs

Different user interfaces

Desktop/WorkgroupSolutions

WiringCloset/Backbone

Solutions

Cisco 1548 MicroSwitch 10/100

Catalyst3000 series

Catalyst 2900series XL

Catalyst1900/2820 series

Catalyst2900 series

Catalyst

5000 series

Catalyst8500 series

Catalyst Switch Products


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Selection Issues:

Scale of the routing features needed

Port density/variety requirements

Capacity and performanceCommon user interface

Cisco700/800Series

Cisco1600/1700

Series

Cisco2500

Series

Cisco3600Series

AS

5000Series

Small Office Solutions

Branch Office Solutions

Central Site Solutions

Cisco12000 GSR

Series

Cisco4000

Series

Cisco7000

Series

Home Office Solutions

Cisco2600Series

Cisco Router Products


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Visual Objective

Use the product selection tool toselect Cisco Equipment


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Summary

After completing this chapter, you shouldbe able to perform the following tasks:

Describe how data moves through a network

Identify the roles and functions of routers,switches and hubs, and specify where eachdevice best fits in the network

Select the appropriate Cisco equipment for anetwork that combines switching, routing andremote access requirements

icnd02_internetwork concepts overview

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